Janus Metal-AIEgen Framework@Hydrogel Patch for Ultrasensitive, Multivariate Responsive, and Intelligent...

Point-of-care testing (POCT) techniques showcase convenience, low cost, and broad applications in public security and laboratory medicine. Hydrogel-based POCT has drawn great interest because of its improved stability and interference resistance. Here, we synthesize high quantum yield metal-AIEgen frameworks (MAFs) and explore stacking heterogeneous hydrogel thin film complexes to prepare a Janus BP@GA hydrogel patch for multianalyte and ultrasensitive intelligent POCT sensors. The aqueous swelling difference renders the Janus hydrogel patch with physical self-sorting behavior for image-based digital recognition. Combined with the fluorescence encoding capacity of MAFs, the Janus BP@GA hydrogel patch achieves fast digital sensing of multianalytes based on customized mobile app-actuated image recognition arithmetic, for example, the intelligent determination of four halide ions. Owing to excellent sensing performance, we develop the BP hydrogel patch coupling with a nonenzymic dual cascade amplification system (H₂O₂-I^-) for ultrasensitive pathogen detection. The limit of detection is 3 CFU/mL for Staphylococcus aureus, staying at the same level compared with enzymic nucleic acid tests but over 100 times more sensitive than other chromogenic/fluorimetric sensors. Clinical bacterial strain tests showed 100% accuracy (n = 28). Fluorescent MAF@hydrogel patch-based ultrasensitive and intelligent digital sensing represents a powerful and convenient POCT platform for developing multiplex and ultrasensitive biochemical sensors from ions to cells.